UF scientists conduct eye study
Published: Tuesday, January 8, 2008 at 6:01 a.m.
Last Modified: Tuesday, January 8, 2008 at 12:00 a.m.
In a first-of-its-kind safety research study, University of Florida scientists have injected an anti-inflammatory compound into the eye of patients with a disease that was robbing them of their sight.
Age-related macular degeneration, or AMD, is the leading cause of vision loss in Americans over the age of 60. Although it causes no pain, it blurs the central vision essential for such day-to-day tasks as reading or driving.
The "wet" form of AMD comes on quickly; an early symptom is that straight lines appear wavy. New blood vessels begin to grow at the back of the eye, often leaking blood and fluid and quickly stealing central vision.
To date, although wet AMD can be treated by a number of means, none offers a cure.
The approach now being tried by a team of researchers in Florida, New Hampshire, Minnesota and Arizona will test the safety and effectiveness of a synthetic peptide - a small protein fragment - in procedures involving the human eye.
In essence, explains Dr. Shalesh Kaushal, scientists are tackling the wet form of macular degeneration from the roots up. "All patients with macular degeneration have good peripheral, or side, vision. It's their central vision that's affected," said Kaushal, an assistant professor of ophthalmology and director of the vitreoretinal service in the UF department of ophthalmology.
Drugs injected into the eye to stem the abnormal growth of blood vessels benefit only the 15 percent of patients afflicted with the wet form of AMD, leaving the vast majority of those with macular degeneration in the dark.
A series of reports two years ago in the journal Science shed light on the underlying mechanisms of macular degeneration. The reports revealed a link between the chronic inflammation and tissue damage that accompany both forms of the disease and a genetic defect in the complement system, a series of enzymes that defend the body against pathogens by stimulating a potent inflammatory response.
"Complement is a set of proteins that are often triggered in inflammatory diseases, including the eye in particular," Kaushal said. "There are now multiple reports that these complement proteins may be overstimulated in wet macular degeneration."
Researchers from Potentia Pharmaceuticals, which is funding the safety trial at UF, developed a family of complement inhibitors called Compstatin for use in the human eye. A derivative of the peptide called POT-4 has been shown to be a much more active version of the original compound.
The complement inhibitors have been shown to prevent the inflammatory response that accompanies both wet and dry macular degeneration in animal studies. Now the focus has shifted to human trials.
Three patients (two at UF and one in New Hampshire) with wet AMD have received injections of POT-4, and a committee will evaluate the safety of the peptide in the eye. If all goes well with these first patients, 12 additional subjects will participate in the study.
Diane Chun can be reached at 352-374-5041 or firstname.lastname@example.org
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